Analog and digital audio content is customarily originated, captured, stored, and delivered to consumers via analog and digital media of various types. For example, CDs, DVDs, BDs, magnetic tape, LP records, film prints, digital files and streams are used with various inherent limitations and benefits to deliver sufficient fidelity to be enjoyed by consumers. The benefits and drawbacks of many of the aforementioned origination, capture, storage and transmission media and means are well known.
Each listener brings a personal set of perceptual characteristics to his or her experience of hearing. Because of natural differences between each listener's hearing acuity and perceptual apparatus, individual listeners may experience audio content differently from the same content as it is experienced by another person, for example by the content producer. Natural frequency, dynamic, and time domain deviations may exist among different listeners, including between each ear among listeners. These naturally occurring differences may include differences in apparent sound intensity, pitch, thresholds such as ‘the threshold of audibility’ at different frequencies, and sensitivity to positional cues.
Creative producer mixes of popular music and movie/episodic soundtracks are available, each highlighting creative choices that may emphasize certain audio characteristics such as frequency response curves and balance, dynamics, or single channel, stereo or multichannel effects such as surround, echo, delay or other positional cues. However, physical characteristics of each listener's outer and inner ears, and each listener's perceptual biases, influence what each listener hears when listening to the same audio recording, even when using identical sound reproduction equipment in identical environments. Such differences may cause subtle impediments to communication between the producer and listener, by preventing the listener from subjectively perceiving what the creative producer intended.
The creative intent in presenting a particular audio recording—sometimes referred to as a “mix”—may include offering listeners a particular listening experience, for example a listening experience that includes a certain frequency balance, dynamics, and surround sound field. Although origination, capture, storage, and delivery systems for audio reproduction are often exactingly managed in an attempt to provide high fidelity to the source content, each listener's ears and perceptual biases may nonetheless influence their hearing experience in uncontrolled ways when listening to an audio recording using a player device. Thus, the subjective experience of listeners may not match the acoustic experience intended by the content producer, despite careful attention to high-fidelity reproduction in the audio player and listening environment.
These and other limitations of prior methods for processing audio content for high-fidelity may be overcome by the novel methods and apparatus disclosed herein.